.container-fluid {
    background-color: darkred;
}

.col-md-2 {
    margin: 0;
    padding: 0;
    width: 200px;
    height: 600px;
    background-color: #f1f1f1;
    border-radius: 5px;
    border: 1px solid #555;
    text-align: center;
}

.left-menu {
    float: left;
}

.right-content {
    float: left;
}

.search {
    text-align: center;
}

table {
    text-align: center;
}

th {
    text-align: center;
}

#ul_head {
    background-color: grey;
}

.active {
    background-color: dimgrey;
    color: white;
}

#li_head1 a:hover:not(.active) {
    background-color: #555;
    color: white;
}

#li_head2 a:hover:not(.active) {
    background-color: #555;
    color: white;
}

#li_head3 a:hover:not(.active) {
    background-color: #555;
    color: white;
}

#td_content {
    text-align: left;
}

.auto_hidden {
    width:204px;
    border-top: 1px solid #333;
    border-bottom: 1px solid #333;
    border-left: 1px solid #333;
    border-right: 1px solid #333;
    position:absolute;
    display:none;
}

.auto_show {
    width:204px;
    border-top: 1px solid #333;
    border-bottom: 1px solid #333;
    border-left: 1px solid #333;
    border-right: 1px solid #333;
    position:absolute;
    z-index:9999; /* 设置对象的层叠顺序 */
    display:block;
    font-size: 17px;
}

.auto_onmouseover{
    color:#ffffff;
    background-color:highlight;
    width:100%;
}

.auto_onmouseout{
    color:#000000;
    width:100%;
    background-color:#ffffff;
}